This invention relates generally to the assembly of workpieces and, more particularly, to a system and method for adjusting bearings or the like.
The assembly of workpieces, such as machinery having rotating parts, frequently requires the precise fitting of antifriction rolling elements such as ball or roller bearings. Tolerances of the manufactured workpiece parts may cause variations in the axial dimensions of the workpiece which may exceed allowable variations for the fitting of bearings therein.
For example a hub upon which a wheel is mounted, for instance, to rotate about a spindle. Such bearings may comprise roller bearings, for example, tapered roller bearings. The spindle may comprise, for instance, an axle or a shaft.
A typical tapered roller bearing includes a cone having an inner race for mounting on a spindle, a cup having an outer race for mounting in a hub, and a plurality of roller elements within a roller cage positioned between the inner and outer races. Commonly, a pair of such tapered roller bearings are mounted on a spindle for rotation thereabout of a wheel mounted on a hub. Cooperating bearings, such as a pair of tapered roller bearings, may be included in a bearing assembly.
In order to properly secure bearings in many axle, spindle, and transmission assemblies, it is necessary to retain the pair of bearings tightly under a predetermined axial load on the shaft or axle, so that they will maintain the proper running clearance of the roller elements under the influence of the combined axial and radial forces which they are designed to support.
One approach to assembling or preloading a bearing arrangement is disclosed in U.S. Pat. No. 4,214,465 to Rode. The preloading or adjustment incorporates use of a deformable spacer which is assembled with the bearings using a hydraulic ram assembly.
Thus, a need exists for a system improving ease, accuracy, and control of adjustment, fitting, assembling, or tailoring of workpieces, e.g. bearing assemblies and spacers thereof.
The present invention provides, in a first aspect, a spacer adjustment system for adjusting at least one spacer of a device. The system includes a ram assembly, a contact detector for operatively detecting a contact between the ram assembly and the device, a motor operatively connected to the ram assembly for operatively applying a force to the device, and a controller, operatively connected to the contact detector, for controlling the motor to adjust the at least one spacer.
The present invention provides in the second aspect, a method for adjusting at least one spacer of a device. The method includes providing a ram assembly, providing a contact detector for operatively detecting a contact between the ram assembly and the device, providing a motor operatively connected to the ram assembly for operatively applying a force to the device, and providing a controller, operatively connected to the contact detector, for controlling the motor to adjust the at least one spacer.
The present invention provides, in a third aspect, a contact detector for use in spacer adjustment apparatus. The detector includes a first electrical contact located on the ram assembly, a second electrical contact located on an adaptor shaft connectable to a workpiece, a controller coupled to the first electrical contact and the second electrical contact, and wherein the controller is adapted to determine an abutting of the first electrical contact and the second electrical contact.
The present invention provides, in a fourth aspect, a space adjustment system for adjusting at least one spacer of a device. The system includes a ram assembly, a means for detecting an initial position of engagement of the ram assembly with at least one spacer, a motor operatively connected to the ram assembly for operatively applying a force to the device, and a controller, operatively connected to the means for detecting, for controlling the motor to adjust the at least one spacer.